The wireless data industry is growing rapidly. New generations of wireless technologies and users thereof demand intelligent and powerful products. New technology-based platforms to meet these growing requirements are being developed. For example, developers of next generation wireless, mobile, and handheld data devices require integrated circuit (IC) devices that balance performance and low power consumption, as well as a reduction in components and an expansion in storage options to meet form factor and system requirements. A current trend in the development of new mobile platforms for wireless, mobile, and handheld devices is to incorporate multiple processors in a device. Each processor may be highly specialized to perform very specific functions such as communications and data processing. For example, mobile platforms are now beginning to incorporate multiple processors with the opportunities in the future of incorporating many more highly specialized and optimized processors. For example, in mobile platforms, communication processors are used for communications related functionality and applications processors are used for computation intensive data applications. In conventional multi-processor mobile platforms, each processor may include its own specific internal oscillator circuit to generate the clock signals to drive the processors and other logic devices. Each internal oscillator circuit are either driven by separate independent external oscillator networks that may include, for example, a network of crystals and capacitors or are ported from one processor to another through dedicated input/output pins.
In some mobile platforms that include multiple processors, each processor has an internal oscillator circuit connected to its own external oscillator network that includes an independent crystal and capacitors network. In other mobile platforms, clock signals are ported from one processor to another. In some applications, because of the independent oscillator networks, the mobile platform may require numerous additional external components to condition and synchronize the clock signals between the multiple processors. Conventional processors generally include an oscillator input port to receive an oscillator input from an external oscillator network to generate its clock signal. Such processors also include separate clock input and output ports to receive clock signals from other processors or to provide an internally generated clock signal to another processor. Thus, each processor in a multi-processor platform may require two additional input/output ports, one to receive a clock signal from another processor and one to provide a clock signal to another processor or logic device on the mobile platform. Providing separate external oscillator networks to each internal oscillator circuit increases overall cost due to the increase in component count and reduces overall reliability of such mobile platforms. Porting clock signals require the use of extra input/output pins in the processor that are separate from the crystal network input pins. Both implementations require additional real estate either at the chip level or the platform level.
In one example, a conventional multi-processor mobile platform may include a communication processor and an application processor, among other processors. An external oscillator network is connected to the oscillator input of the application processor from which the application processor generates a 32 kHz clock signal. The 32 kHz clock signal is then ported through an output pin of the application processor to the clock input pin of the communication processor. The communication processor may include an automatic amplitude control (AAC) oscillator, which may be sensitive to the slew rate of the 32 kHz clock signal provided by the application processor. Thus, additional signal conditioning circuits and components may be required to condition and synchronize the clock signal from the application processor to make it compatible with the communication processor clock signal requirements.